ARMY TM 9-4120-380-14
AIR FORCE TO 35E9-136-21
4.35 PHASE RELAY (K6). This task covers inspection, testing, removal, installation and adjustment.
Tool kit, service, refrigeration unit (Item 1, Appendix B)
Disconnect input power to the air conditioner before performing any internal
maintenance Voltages used can KILL. Shutting the unit off at the control panel does not
disconnect unit power.
(1) Disconnect air conditioner input power at source, and
Inspect for cracks, corrosion, loose electrical connections, and loose mounting hardware. Replace relay if damaged (see
The following test must be conducted with power on. Use extreme caution and follow
steps carefully. Death or serious injury may result.
a. Turn on external electrical power.
b. Set MODE SELECT switch to AUTO.
Turn relay failure level adjustment (3) fully clockwise. Check that indicator unit (2) comes on.
d. Turn relay failure level adjustment (3) slowly counterclockwise until indicator light goes out Adjust set point
voltage by measuring across relay socket (1), terminals 3 to4, 3 to 5, and 4 to 5 (see fig FO-2.) Set point voltage
should be 185 + 5 Vac across each phase
e. If relay fails above testing and adjustment, replace relay
Set MODE SELECT switch OFF.
g. Turn external electrical power off.